- Redesigned hashline edit API to use discriminated union variants (replaceLine, replaceLines, insertAfter, insertBefore, substr) instead of nested src/dst structure.
- Changed hash algorithm from xxHash64 hex to xxHash32 base36 encoding and increased hash length from 2 to 3 characters.
- Added substr edit variant to match and replace content by unique substring when line hashes are unavailable.
- Implemented line relocation heuristics to resolve stale line references when hash uniquely identifies a moved line.
- Moved substr needle search from edit application phase to pre-validation phase for earlier error detection.
- Migrated hashline edit type definitions from manual TypeScript interfaces to schema-derived types using Static<typeof schema> pattern.
- Added `substr` source specification kind to match and replace lines by unique substring without requiring line-hash references.
- Implemented substring matching logic in hashline edits with validation for uniqueness and error handling for not-found and ambiguous cases.
- Added schema definition and type guards for the new `substr` operation type across patch system.
- Added mutation preview hints to error messages when edits fail with 'No changes made' errors, showing line numbers, hashes, and added/removed lines.
- Changed formatter to pin JavaScript fixtures to the flow parser to avoid parser-dependent formatting drift.
- Added whitespace preservation logic to treat whitespace-only differences as passing in file verification.
- Removed substring source specification kind from hashline edits, requiring users to use line-hash references instead.
- Simplified SrcSpec type to use generic type parameter for line references, removing substring variant from union.
- Updated react-edit-benchmark to use --max-tasks option for deterministic task sampling and changed default batch sizes to 1.
- Added computeHashlineDiff function to compute diffs for hashline-based edits without applying them.
- Added support for hashline edits in tool execution with caching mechanism to avoid redundant diff computations.
- Added formatStreamingHashlineEdits function to format and display hashline edits with configurable limits.
- Enhanced EditRenderArgs interface with optional previewDiff and edits fields for hashline mode support.
- Refactored import paths from absolute package-scoped imports to relative imports for better module resolution.
- Added streaming functions `streamHashLinesFromUtf8` and `streamHashLinesFromLines` for processing large files with configurable chunking.
- Added `HashlineStreamOptions` interface to control streaming behavior with `startLine`, `maxChunkLines`, and `maxChunkBytes` options.
- Changed hashline format from 4-character to 2-character hex hashes for more compact output.
- Updated `computeLineHash` function to normalize whitespace and removed line number from hash seed for consistency.
- Improved CLI argument parsing with explicit handling of `--help`, `--version`, and subcommand detection.
- Removed `@types/diff` dev dependency as it is no longer needed.
- Fixed line hash computation to normalize whitespace before hashing, ensuring consistent hashes for semantically identical lines.
- Removed index parameter from hash computation to prevent hash variance based on line position.
- Changed `HashlineEdit.src` from string format (e.g., `"5:ab"`, `"5:ab..9:ef"`) to structured `SrcSpec` object with discriminated union types (`{ kind: "single", ref: "..." }`, `{ kind: "range", start: "...", end: "..." }`, `{ kind: "insertAfter", after: "..." }`, `{ kind: "insertBefore", before: "..." }`, `{ kind: "substring", needle: "..." }`).
- Refactored `parseSrc` function to `parseSrcSpec` to handle structured `SrcSpec` objects instead of string parsing, replacing string validation and delimiter parsing logic with explicit case handling for each operation kind.
- Updated tool schema in `index.ts` to define `srcSpecSchema` as a discriminated union type with five variants, replacing the previous simple string-based `src` parameter definition.
- Added substring-based source matching for hashline edits to support matching lines by content when hash references are unavailable.
- Added automatic detection and repair of single-line merges where models incorrectly combine multiple lines into one.
- Added normalization of Unicode-confusable hyphens to ASCII hyphens to handle model-generated variations.
- Added heuristics to restore indentation and preserve wrapped line formatting during edits.
- Relaxed comma validation in src to allow commas while rejecting inputs with multiple line references.
- Enhanced parseLineRef to accept shorter hash prefixes instead of requiring exact hash matches.
- Improved error messages for hash mismatches to provide more actionable guidance.
- Replaced HashlineEdit API from old/new/after fields to src/dst fields with unified range syntax supporting single lines, ranges, insert-after, and insert-before operations.
- Added parseSrc() function to parse structured line references from src strings supporting formats like '5:ab', '5:ab..9:ef', '5:ab..', and '..5:ab'.
- Added heuristics to strip anchor line echoes and range boundary echoes from model-generated replacement content.
- Implemented preserveWhitespaceOnlyLinesLoose() for improved whitespace preservation using loose matching strategy when replacement line counts don't match.
- Added comprehensive benchmark reports for Claude Sonnet 4.5, Gemini 2.5 Flash Lite, and GPT-5.1 Codex Mini models evaluating hashline edit performance across 60 tasks.
- Added automatic stripping of `LINE:HASH|` display prefixes and unified-diff `+` markers from replacement content in hashline edits.
- Enhanced replace edits to preserve original whitespace on lines where only whitespace differs, preventing spurious formatting diffs when models reformat code.
- Added helper functions `stripNewLinePrefixes()`, `preserveWhitespaceOnlyLines()`, and `equalsIgnoringWhitespace()` to improve edit robustness.
- Added `toArray()` helper function to normalize `string | string[]` inputs for hashline edit operations with comma-separated line reference support.
- Added `HashlineMismatchError` class that displays grep-style output with `>>>` markers for hash validation failures.
- Added `HashMismatch` type for representing individual hash mismatches with line number, expected hash, and actual hash.
- Updated `HashlineEdit` type to accept `string | string[]` for `old` and `new` fields, allowing both singular and plural input formats.
- Reduced hash length from 4 to 2 hex characters (16-bit hashes) for more concise line references.
- Enhanced `parseLineRef()` to strip display-format suffixes and `validateLineRef()` to throw `HashlineMismatchError` with context lines for better error reporting.
- Optimized line hash computation by precomputing hex lookup table and using bitwise operations instead of string formatting.
- Simplified conditional logic in read tool for hash and line number configuration.
- Refactored react-edit-benchmark model/provider parsing to use concise ternary operator.
- Added HashlineMismatchError class with formatted error messages showing mismatched hashes with context lines.
- Added HashMismatch type to represent hash validation errors with line number, expected, and actual hash values.
- Enhanced hash validation in applyHashlineEdits to collect all hash mismatches before applying edits instead of failing on first mismatch.
- Renamed HashlineEdit fields from 'src'/'dst' to 'old'/'new' for improved naming clarity and consistency.
- Added hashline edit mode for line-addressed edits using hash-verified line references with xxHash64 integrity verification.
- Replaced `edit.patchMode` boolean setting with `edit.mode` enum supporting 'replace', 'patch', and 'hashline' modes.
- Added `readHashLines` configuration setting to include line hashes in read output for hashline edit mode.
- Implemented `computeLineHash`, `formatHashLines`, `parseLineRef`, `validateLineRef`, and `applyHashlineEdits` utility functions for hashline operations.
- Updated read tool to support optional `hashes` parameter and prioritize hash lines over line numbers when both are requested.
- Changed `getEditModelVariants()` return type from `Record<string, 'patch' | 'replace'>` to `Record<string, EditMode | null>` and removed hardcoded model-specific defaults.
- Fixed tab character display in error messages and bash tool output by applying replaceTabs() sanitization.
- Added TUI rendering sanitization documentation to AGENTS.md with guidelines for sanitizing text in tool renderers.
- Applied replaceTabs() function to error text in patch shared module to ensure proper tab-to-space conversion.
- Applied replaceTabs() function to bash tool output lines in both expanded and collapsed display modes.
- Fixed patch applicator to preserve indentation in context-only hunks by skipping unnecessary adjustments when pattern equals actual content.
- Implemented linear regression-based tab width inference to correctly convert space-indented diffs to tab-indented files using ax+b model.
- Added regression tests for context-only hunk handling and space-to-tab indentation conversion with offset models.
- Updated patch tool documentation to emphasize never using edit operations for indentation or formatting fixes.
- Fixed tab character rendering in tool output previews and code cell displays by converting tabs to spaces for consistent terminal display.
- Applied replaceTabs() function across patch rendering, write tool output, and code cell output to ensure uniform tab handling.
- Implemented width-aware text truncation across all tool renderers to respect terminal width constraints and prevent output overflow.
- Enhanced render caching to include width parameter for cache invalidation when terminal width changes, improving cache accuracy.
- Migrated truncateToWidth function imports from render-utils to centralized tui module for better code organization.
- Introduced Hasher utility for generating width-aware cache keys in calculator, find, grep, todo-write, and write tools.
- Optimized box component rendering to only truncate lines that exceed content width, reducing unnecessary truncation operations.
- Replaced ASCII ellipsis characters (three dots '...') with Unicode ellipsis character ('...') throughout the codebase for improved typography.
- Adjusted string truncation logic to account for single-character Unicode ellipsis instead of three-character ASCII ellipsis, reducing reserved space from 3 to 1 character in truncation calculations.
- Updated truncation offsets in multiple files (session-manager, agent, executor, footer) to preserve 2 additional characters before ellipsis due to more compact Unicode representation.
- Implemented caching for tool output block rendering to avoid redundant computations on re-renders.
- Enhanced read tool grouping to prevent coalescing across narrative boundaries (text/thinking blocks between tool calls).
- Improved string preview formatting to detect multi-line strings and display line counts with ellipsis indicators.
- Refactored tool execution component to use reactive render state tracking for better state management.
- Enhanced error handling in tool renderers with logging for failures.
- Fixed truncation indicator to use ellipsis character instead of verbose suffix.
- Converted class properties to TypeScript parameter properties across 51 files to reduce boilerplate code.
- Removed explicit field declarations and manual assignments in constructors by using TypeScript's parameter property syntax with access modifiers.
- Applied consistent pattern of declaring private readonly and public readonly properties directly in constructor parameters.
- Migrated all environment variable access from Node.js `process.env` to Bun runtime `Bun.env` API across the entire codebase.
- Updated 71 files including source code, tests, documentation, and configuration to use Bun's native environment variable API.
- Added comprehensive environment variables documentation in `packages/coding-agent/docs/environment-variables.md` covering 100+ environment variables organized by category.
- Updated CHANGELOG entries to reflect migration from `process.env` to `Bun.env` and environment variable prefix changes (PI_* vs OMP_*).
- Maintained identical behavior and logic across all changes - only the environment variable access method was updated.
- Migrated environment variable access from direct process.env to centralized getEnv() utility function across all packages.
- Renamed environment variable prefix from OMP_ to PI_ throughout codebase (e.g., OMP_CODING_AGENT_DIR -> PI_CODING_AGENT_DIR).
- Removed automatic environment variable migration from PI_ to OMP_ prefixes via migrate-env.ts module.
- Removed env setting from configuration schema and applyEnvironmentVariables() method from settings.
- Updated CI/CD build configuration to use PI_COMPILED flag instead of OMP_COMPILED.
- Changed venvPath property in PythonRuntime from nullable (string | null) to optional (string | undefined).
- Added exclusive concurrency mode enforcement to file-modifying tools (edit, write, bash, python, ssh, todo-write) by introducing a new public `concurrency` property set to "exclusive" on each tool class.
- Updated CHANGELOG.md to document the enforcement of exclusive concurrency mode for file-modifying tools.
- Cleaned up imports in tool-execution.ts by removing unused Theme type import and reordering imports for better organization.
- Fixed timeout handling in LSP write-through operations to properly clear formatter and diagnostics results when operations exceed the 10-second timeout threshold.
- Added timeout detection mechanism in LSP index that sets a flag when the timeout signal is aborted.
- Added nonAbortable property to EditTool and WriteTool classes to prevent these operations from being aborted during execution.
- Externalized subagent submit reminder prompt to a separate template file for improved maintainability and dynamic retry tracking.
- Changed TextInput type parameter to string in truncateToWidth(), visibleWidth(), sliceWithWidth(), and extractSegments() functions in native bindings.
- Removed TextInput type export from public API of pi-natives package.
- Removed format.ellipsis symbol from theme configuration, replacing all theme-based ellipsis references with hardcoded Unicode ellipsis character (...).
- Removed ellipsis property from SymbolTheme interface in pi-tui package.
- Removed truncateToWidth, sliceWithWidth, and extractSegments wrapper functions from pi-tui public API, now re-exporting directly from pi-natives.
- Added early return optimizations in truncateToWidth() and sliceWithWidth() native functions to skip native calls when possible.
- Replaced SettingsManager class with new Settings singleton providing synchronous get/set API and background persistence.
- Introduced settings-schema.ts as single source of truth for all configuration definitions with 100+ settings organized into logical groups.
- Migrated from method-based settings access (getTheme(), setTheme()) to path-based access using dot notation (settings.get('theme'), settings.set('theme', value)).
- Removed 2035-line settings-manager.ts file and replaced with modular settings.ts (693 lines) and settings-schema.ts (836 lines) for improved maintainability.
- Unified settings schema into single source of truth eliminating duplicate definitions across settings-defs.ts and settings-manager.ts.
- Extracted manual space padding logic into a reusable `padding()` utility function across all UI components and utilities.
- Optimized padding operations by introducing a pre-allocated 512-space buffer in the `padding()` function to reduce repeated string allocations.
- Updated all imports across 30 files to use the new `padding()` function from pi-tui instead of inline `' '.repeat()` calls.
- Renamed local variables from `padding` to `pad`, `padSize`, `indent`, or `linePad` to avoid naming conflicts with the imported `padding()` function.
- Exported the `padding()` utility function from the tui package index for public use.
- Added persistent shell session support for bash tool with environment variable preservation across commands.
- Added shellForceBasic setting to force bash/sh even if user's default shell is different (default: true).
- Added OMP_SHELL_PERSIST environment variable to control persistent shell behavior (set to 0 to disable).
- Restructured system prompt with coordinator-specific guidance for parallel task delegation.
- Added model-specific edit variant configuration allowing users to specify 'patch' or 'replace' mode per model pattern.
- Added `getEditVariantForModel()` method to determine appropriate edit mode based on user settings and default patterns.
- Made EditTool's `patchMode`, `description`, and `parameters` dynamic properties that adapt based on the active model.
- Added fallback mechanism in model resolution to support tool creation before agent initialization.
- Plan mode provides structured workflow where agents propose plans for user approval before execution.
- Added plan:// internal URL protocol for accessing plan files and injecting plan-mode context into subagent prompts.
- Added plan mode toggle shortcut and paused status indicator in status line.
- Fixed plan reference injection to properly pass workflow state to plan-mode system prompts.
- Improved autocomplete fuzzy matching to support subsequence matching for skill suggestions.
- Removed Prettier configuration files (.prettierignore and .prettierrc) and migrated formatting to Biome.
- Updated Biome configuration from version 2.3.11 to 2.3.12 and changed arrowParentheses rule from 'always' to 'asNeeded'.
- Pinned @biomejs/biome dependency to exact version 2.3.12 in package.json and bun.lock.
- Applied consistent arrow function formatting across 489 files by removing unnecessary parentheses around single parameters.
- Removed blank lines after comment blocks and reorganized imports for consistency across the codebase.
- Converted readdirSync, readFileSync, and statSync to async readdir, readFile, stat across skills and agent discovery.
- Made scanDirectoryForSkills async and refactored custom directory scanning to use Promise.all for concurrent processing.
- Updated agent discovery to use fs/promises for async file reading and refactored helper patterns.
- Added AgentParsingError exception class for better error handling during agent parsing.
- Added filesystem error type guards (isEnoent, isEacces, isPerm, etc.) to pi-utils for safe error checking.
- Added color manipulation utilities to pi-utils for accessibility features.
- Added color-blind mode setting to settings manager.
- Migrated plugins, settings, and config modules from sync to async file operations.
- Updated error handling to use new pi-utils type guards for type-safe checking.
- Removed WASM generation script; use Bun `wasm?raw` loader for imports.
- Added bunfig.toml with loaders for `.md`, `.py`, and `.wasm?raw` text imports.
- Added types/assets/index.d.ts for global TypeScript module declarations.
- Unified TypeScript configuration with tsgo-based checking across monorepo.
- Removed build and WASM steps from install and publish pipelines.
- Added tsconfig.publish.json files to all packages with optimized publish-time configuration.
- Updated all package.json scripts with prepublishOnly hooks for correct type checking during publish.
- Added @oh-my-pi/omp-stats path mappings to root tsconfig.json for consistent imports.
- Added WASM generation script for photon module and integrated into install:dev script.
- Fixed indentation and line breaks in nested code blocks (lsp/render.ts, patch/shared.ts).
- Collapsed overlong function arguments and ternary expressions to standard line length.
- Reorganized import statements for consistency (ask.ts).
- Improved readability of conditional expressions (output-block.ts, web/search/render.ts, python.ts).
- Output block border color now reflects state (error, success, warning) for visual feedback.
- Tools use renderStatusLine, renderTreeList, renderFileList, renderCodeCell for unified formatting.
- Write tool shows streaming preview of content being written with syntax highlighting.
- Read tool displays resolved path information when reading from URLs or symlinks.
- Calculator shows expression and output (e.g., `2+2 = 4`) instead of just the result.
- Empty and error states render consistently with status headers across Find, Grep, Ls, Notebook, Ask.
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